The present invention relates to an improved cylindrical working member and system employing same. In the prior art, it is known to employ a cylinder as a working member. However, in cylindrical working members known to Applicant, complicated machining steps are employed in manufacturing the working member. These machining steps add significant cost. As such, a need has developed for a working member that can be manufactured simply and cheaply and that will have the versatility to be used individually, in a telescoping cylinder system, and in other environments of use.
The following prior art is known to Applicant: PA1 U.S. Pat. No. 2,308,761 to Komph, Sr. PA1 U.S. Pat. No. 2,657,960 to Latimer-Needham PA1 U.S. Pat. No. 2,854,958 to Wood et al. PA1 U.S. Pat. No. 3,115,071 to Strader PA1 U.S. Pat. No. 3,312,150 to Strader PA1 U.S. Pat. No. 3,452,647 to Herrell PA1 U.S. Pat. No. 3,631,765 to Neumeister PA1 U.S. Pat. No. 3,934,423 to Haller PA1 U.S. Pat. No. 4,195,714 to Massing PA1 U.S. Pat. No. 4,516,468 to Sheriff PA1 U.S. Pat. No. 4,541,325 to Sheriff PA1 U.S. Pat. No. 4,691,617 to Purkott PA1 U.S. Pat. No. 4,926,745 to Cioletti.
Of the references listed above, Komph, Sr., Wood et al., Herrell, Neumeister, Haller, Massing, Sheriff '468, Sheriff '325, and Purkott teach telescoping cylinder systems in which a plurality of individual cylinders are assembled together to allow telescoping. In each of these references, complicated machining steps are employed in the manufacturing process, including manufacturing of a multiplicity of grooves, creation of integral shoulders, and the like. The present invention differs from the teachings of these references as contemplating making such a cylinder of a stock cylindrical tube with a minimal number of grooves machined therein and the use of low friction snap rings and seals to contain fluid pressure.
Latimer-Needham teaches a piston having a complicated structure including an integral shoulder designed to contain seal rings. No such integral shoulders are required in the present invention.
Strader '071 and '150 teach a reciprocating hydraulic motor employing a sleeve mounted on a post and having a plurality of seals and rings mounted on the periphery thereof. Strader '071 and '150 require the machining of a deep groove in the sleeve with seals and rings mounted to each side thereof. Such structure is unnecessary in the present invention.
Cioletti teaches a pull rod assembly wherein a rod has several grooves machined in the outer periphery thereof and a complicated seal mechanism is mounted thereon and retained in place for the use of a split retainer ring and a "TRUE ARC" ring. While Cioletti teaches an improvement over the prior art, the present invention relates to a cylinder, not a rod, and contemplates a simple seal system merely employing simple O-rings and low friction snap rings to retain them in place.
Applicant's prior U.S. Pat. No. 5,341,724 discloses a pneumatic telescoping cylinder and method wherein each of the stages of the telescoping cylinder system employs somewhat complicated machining steps and seal members having complicated shapes. The teachings of the present invention may be employed to simplify the system described in Applicant's prior Patent and the actuating system disclosed herein may also be employed in actuating the telescoping cylinder of Applicant's prior Patent.